Recalculation of the temperature of the inner surface of the fence, obtained as a result of tests, to the design temperature conditions

GOST 26254-84: Buildings and structures. Methods for determining the heat transfer resistance of enclosing structures (replaced by GOST R 56623-2015)

Date of introduction 01/01/1985

GOST 26254-84

UDC 624.01.001.4:006.354

Group Zh39

STATE STANDARD OF THE USSR UNION

Buildings and constructions

Methods for determining heat transfer resistance

enclosing structures

Buildings and structures.

Methods for determination of thermal resistance

of enclosing structures

Date of introduction 1985-01-01

Information data

1. DEVELOPED

Research Institute building structures(NIISK) USSR State Construction Committee

Central Research and Design Institute of Standard and Experimental Housing Design (TsNIIEPzhilishcha) of the State Civil Engineering

DEVELOPERS

I.G. Kozhevnikov, Ph.D. tech. Sciences (topic leader); I.N. Butovsky, Ph.D. tech. sciences; V.P. Khomenko, Ph.D. tech. sciences; G.G. Farenyuk, Ph.D. tech. sciences; E.I. Semenova, Ph.D. tech. sciences; G.K. Avdeev, Ph.D. tech. sciences; A.P. Tsepelev, Ph.D. tech. sciences; I.S. Lifanov

Research Institute of Building Physics (NIISF) of the USSR State Construction Committee

Director V.A. Drozdov

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee for Construction Affairs dated August 2, 1984 No. 127

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

Item number,

applications

GOST 12.1.005-88

GOST 12.1.013-78

GOST 1790-77

GOST 3044-84

GOST 6376-74

GOST 6416-75

GOST 6651-84

GOST 7076-87

GOST 7164-78

GOST 7165-78

GOST 7193-74

GOST 8711-78

GOST 9245-79

GOST 9736-91

GOST 9987-77

GOST 11161-84

GOST 22787-77

GOST 23215-78

GOST 24104-88

GOST 25891-83

GOST 27544-87

6.11, Appendix 7

3.4, Appendix 1

3.4, appendix 1

3.4, 6.5, Appendix 1

3.9, Appendix 1

3.5, Appendix 1

Annex 1

3.9, Appendix 1

3.6, Appendix 1

3.8, Appendix 1

3.3, 4.12, 5.4, Appendix 3

3.4, Appendix 1

OST 16.0.801.397-87

OST 26-03-2039-87

TU 25-05.2792-82

3.8, Appendix 1

5.REISSUE. April 1994

This standard applies to enclosing structures of residential, public, industrial and agricultural buildings and structures: external walls, coverings, attic floors, floors over passages, cold undergrounds and basements, gates and doors in external walls, other enclosing structures separating rooms with different temperature and humidity conditions, and establishes methods for determining their resistance to heat transfer in laboratory and full-scale (operational) winter conditions.

The standard does not apply to translucent enclosing structures.

Determining the heat transfer resistance of enclosing structures makes it possible to quantify the thermal technical qualities of the enclosing structures of buildings and structures and their compliance regulatory requirements, establish real heat losses through external enclosing structures, check design and design solutions.

1. General Provisions

1.1. Heat transfer resistance, which characterizes the ability of the enclosing structure to resist the heat flow passing through it, is determined for sections of the enclosing structure that have a uniform surface temperature.

1.2. The reduced resistance to heat transfer is determined for enclosing structures that have heterogeneous areas (joints, heat-conducting inclusions, vestibules, etc.) and the corresponding uneven surface temperature.

1.3. Methods for determining heat transfer resistance based on creating stationary heat exchange conditions in the building envelope and measuring the temperature of the internal and outside air, temperature of the surfaces of the enclosing structure, as well as the density of the heat flux passing through it, from which the corresponding required values are calculated using formulas (1) and (2) of this standard.

1.4. The heat transfer resistance of the enclosing structure is determined by testing in laboratory conditions in climatic chambers, in which a temperature and humidity regime close to the design winter operating conditions is created on both sides of the tested fragment, or under natural operating conditions of buildings and structures in winter.

2. Sampling method

2.1. Heat transfer resistance in laboratory conditions is determined on samples, which are entire elements of factory-made enclosing structures or their fragments.

2.2. The length and width of the tested fragment of the enclosing structure must be at least four times greater than its thickness and be at least 1500x1000 mm.

2.3. The procedure for selecting samples for testing and their number are established in standards or technical conditions on specific enclosing structures. If these documents do not indicate the number of samples to be tested, at least two samples of the same type are selected for testing.

2.4. When testing in climatic chambers, joints, abutments and other types of connections between elements of enclosing structures or their fragments must be made in accordance with the design solution.

2.5. Heat transfer resistance under natural conditions is determined on samples, which are the enclosing structures of buildings and structures in operation or fully prepared for commissioning, or specially built pavilions.

2.6. During full-scale testing of external walls, walls are selected in corner room on the ground floor, oriented to the north, northeast, northwest and additionally, in accordance with the tasks being solved, to other sides of the horizon, the most unfavorable for the given area (predominant winds, oblique rains, etc.), and on another floor.

2.7. For testing, at least two similar enclosing structures are selected, with inside which maintain the same temperature and humidity conditions in the premises.

3. Apparatus and equipment

3.1. To determine the heat transfer resistance of enclosing structures in laboratory conditions, a thermally insulated climatic chamber is used, consisting of warm and cold compartments separated by the structure being tested.

To complete the climatic chamber, the following equipment is used:

compressors with a cooling capacity of at least 3.5 kW or compressor-condenser units of refrigeration machines in accordance with OST 26-03-2039, installed outside the chamber, and cooling batteries refrigeration units installed inside the cold compartment to cool the air in it;

oil-filled electric radiators in accordance with GOST 16617, thermoradiators, electric fan heaters in accordance with GOST 17083 or electric convectors in accordance with GOST 16617 and electric air humidifiers for heating and humidifying the air in the warm compartment of the chamber;

temperature regulators in accordance with GOST 9987, automatic servo balancing devices in accordance with GOST 7164 or temperature alarms in accordance with GOST 23125 for automatically maintaining the set temperature and air humidity in the chamber compartments.

It is allowed to use a climatic chamber consisting of a cold compartment, into the opening of which the tested fragment is mounted, and an attached warm compartment, as well as other equipment, provided that they are provided in the cold and warm compartments of the chamber in a stationary mode corresponding to the design winter operating conditions of the enclosing structure.

3.2. To determine the resistance to heat transfer under natural operating conditions of buildings, the temperature difference that has established on the enclosing structure due to the difference in temperature of the external and internal air is used. To maintain a constant indoor air temperature, use the equipment and means of regulation specified in clause 3.1.

3.3. To measure the density of heat flows passing through the building envelope, instruments in accordance with GOST 25380 are used.

3.4. To measure temperatures, thermoelectric converters in accordance with GOST 3044 with wires made of chromel, copel and alumel alloys in accordance with GOST 1790 (thermocouples), copper resistance thermal converters in accordance with GOST 6651 and thermistors (thermometers, resistance) are used as primary transducers.

As secondary measuring instruments, working with thermoelectric thermometers and heat flow converters, use potentiometers direct current according to GOST 9245, millivoltmeters according to GOST 8711 or according to GOST 9736. Resistance thermometers are connected to DC measuring bridges according to GOST 7165.

To quickly measure the temperature field of the surfaces of the enclosing structure, temperature probes, thermoradiometers, and thermal imagers are used (see Appendix 1).

The air temperature is controlled using glass expansion thermometers in accordance with GOST 112 (lower limit minus 70°C) and GOST 27544.

It is allowed to use other primary temperature transducers and devices certified in in the prescribed manner.

3.5. To continuously record the nature of changes in indoor air temperature, thermographs are used in accordance with GOST 6416.

3.6. To measure the difference in air pressure on both sides of the structure being tested, a micromanometer MMN according to GOST 11161 is used.

3.7. To measure relative air humidity, aspiration psychrometers are used, and to record the nature of changes in humidity, hygrographs are used according to the current regulatory and technical documentation.

3.8. To determine the moisture content of building envelope materials, cups of the SV or SN type in accordance with GOST 25336, an electric drying cabinet in accordance with OST 16.0.801.397, laboratory standard scales with a maximum weighing limit of 200 g in accordance with GOST 24104, and desiccators in accordance with GOST 25336 are used.

3.9. Wind speed in natural conditions is determined with a hand-held anemometer according to GOST 6376 or GOST 7193.

3.10. To check the operation of the climate chamber equipment, measuring equipment and heat exchange conditions in the warm and cold compartments of the chamber, use a control fragment with a known thermal resistance within 1-2 (m 2 °C)/W, dimensions which must correspond to the dimensions and configuration of the opening into which the structure being tested is installed. Design solution and the material of the control fragment must ensure that its thermal properties remain constant over time. The climate chamber is checked at least once a year.

3.11. The list of instruments and equipment for determining the heat transfer resistance of enclosing structures in laboratory and field conditions is given in Appendix 1.

4. Preparation for testing

4.1. Preparation for the experimental determination of the heat transfer resistance of the enclosing structure begins with the preparation of a test program and a layout of the primary temperature and heat flow transducers. The test program determines the type of test (laboratory, pavilion, full-scale), objects, area, approximate dates, volume of tests, types of enclosing structures, controlled sections and other data necessary to solve the problem.

4.2. The layout of the primary temperature and heat flow transducers is drawn up on the basis of the design solution of the structure or according to a pre-established temperature field of the surface of the enclosing structure being tested. To do this, when testing in climatic chambers or pavilions, the fully assembled enclosing structure is subjected to temporary thermal exposure using the equipment specified in clause 3.1, after which, without waiting for the establishment of a stationary mode, in order to identify heat-conducting inclusions and thermally homogeneous zones, their configuration and sizes , remove the temperature field using a thermal imager, thermoradiometer or temperature probe. The contours of the main temperature zones, based on the results of thermography, are applied to the surface of the enclosing structure.

During full-scale tests, they immediately begin to measure surface temperatures and establish thermally homogeneous zones and locations of heat-conducting inclusions.

4.3. The thermal imager is installed in such a way that, if possible, the entire structure is in the field of view. Thermograms obtained on the monitor are recorded using a camera or video recorder. It is possible to obtain an image of the entire area of the tested fragment of the enclosing structure by sequential thermography of sections.

4.4. When measuring temperatures with a temperature probe, the internal and external surfaces of the enclosing structure are divided into squares with sides no more than 500 mm. Zones with heat-conducting inclusions are divided into smaller squares in accordance with design features. The surface temperature is measured at the vertices of these squares and directly against the heat-conducting inclusions. Temperature values are applied to the sketch of the enclosing structure. Points with equal temperatures are connected by isotherms, and the configuration and dimensions of isothermal zones are determined. To identify thermally homogeneous areas, it is permissible to limit oneself to measuring temperatures inner surface enclosing structure if it is impossible to measure temperatures from the outside.

4.5. Primary temperature and heat flow converters are located in accordance with the diagram. An example of a diagram for placing thermocouples along the cross section and on the surface of the enclosing structure and connecting them to measuring equipment is given in Appendix 2.

If necessary, the layout of the primary sensors is specified based on the results of thermography of the surface of the tested enclosing structure.

4.6. To determine the heat transfer resistance of a part of the enclosing structure that is uniform in surface temperature, temperature and heat flow converters are installed in at least two characteristic sections with the same design solution.

4.7. To determine, temperature sensors are placed in the center of thermally homogeneous zones of fragments of the enclosing structure (panels, slabs, blocks, monolithic and brick parts of buildings, doors) and additionally in places with heat-conducting inclusions, in corners, at joints.

4.8. To measure the thermal resistance of individual layers of the enclosing structure, sensitive elements of thermal sensors are mounted in sections according to clause 4.6 in the thickness of the fragment of the enclosing structure during its manufacture with a step of 50-70 mm and for multilayer structures additionally at the boundaries of the layers.

4.9. If there are ventilated layers in the enclosing structures, the sensitive elements of temperature sensors are installed with a pitch of at least 500 mm on the surfaces and in the center of the layer.

Heat flow converters are fixed on the inner and outer surfaces of the fence being tested, at least two on each surface.

4.10. To measure internal air temperatures, the sensitive elements of temperature sensors are installed vertically in the center of the room at a distance of 100, 250, 750 and 1500 mm from the floor and 100 and 250 mm from the ceiling. For rooms with a height of more than 5000 mm, vertical temperature sensors are installed additionally in increments of 1000 mm.

To measure the temperatures of indoor and outdoor air near the building envelope, temperature sensors are installed at a distance of 100 mm from the inner surface of each characteristic zone and at a distance of 100 mm from the outer surface of at least two characteristic zones.

4.11. The sensitive elements of the temperature sensors are tightly attached to the surface of the structure being tested.

When using thermocouples, it is allowed to fix them on the surface of the enclosing structure using adhesives: gypsum or plasticine, the thickness of which should be no more than 2 mm. The degree of blackness of the adhesive materials used should be close to the degree of blackness of the surface of the enclosing structure.

In this case, the thermometric wire is removed from the place where the sensitive element is attached along the surface of the enclosing structure in the direction of isotherms or the minimum temperature gradient to a length of at least 50 wire diameters. Resistance electrical insulation between the thermal converter circuit and the external metal fittings there must be at least 20 MOhm at a temperature (and relative air humidity of 30 to 80%).

The free ends of the thermocouples are placed in a thermostat with a temperature of . It is allowed to use a Dewar vessel as a thermostat. At the same time, it must contain steam, water and ice of distilled water at the same time.

The thermocouples are connected to the secondary measuring instrument through an intermediate multipoint switch.

4.12. To measure the heat flux density passing through the enclosing structure, one heat flux transducer is installed on its inner surface in each characteristic zone. Heat flow converters on the surface of the enclosing structure are fixed in accordance with GOST 25380.

4.13. To measure the difference in air pressure, the ends of the hoses from the micromanometer are placed on both sides of the structure under test at a level of 1000 mm from the floor.

4.14. Hygrographs, hygrometers, aspiration psychrometers and thermographs, designed to control and regulate temperature and relative humidity, are installed in the center of the room or compartment of the climate chamber, at a height of 1500 mm from the floor.

4.15. When testing in a climate chamber, after checking the readiness of the equipment and measuring instruments, the warm and cold compartments are isolated from the outside air using sealed doors. The control equipment sets the set temperature and air humidity in each compartment and include refrigeration, heating and air-humidifying equipment of the chamber.

5. Testing

5.1. When testing in laboratory conditions, the temperature and relative humidity of the air in the climate chamber compartments are maintained automatically with accuracy and %.

5.2. Temperatures and heat flow densities are measured after reaching a stationary or close to it mode in the tested enclosing structure, the onset of which is determined by control measurements of temperatures on the surface and inside the tested structure.

After establishing a given air temperature in the climatic chamber compartments, measurements are carried out for enclosing structures with thermal inertia up to 1.5 in no less than 1.5 days, with thermal inertia from 1.5 to 4 - after 4 days, with thermal inertia from 4 to 7 - after 7 days, and with thermal inertia over 7 - after 7.5 days.

The thermal inertia values of enclosing structures are determined by building regulations and the rules approved by the USSR State Construction Committee.

The number of measurements in a stationary mode must be at least 10 with a total measurement duration of at least 1 day.

5.3. Tests under natural conditions are carried out during periods when the difference between the average daily temperatures of external and internal air and the corresponding heat flow provide a result with an error of no more than 15% (see Appendix 3).

The duration of measurements under natural conditions is determined based on the results pre-treatment measurement data during testing, which takes into account the stability of the outside air temperature during the test period and in the previous days and the thermal inertia of the enclosing structure. The duration of measurements under natural operating conditions should be at least 15 days.

5.4. The heat flux density passing through the enclosing structure is measured according to GOST 25380.

5.5. The temperature and humidity of the internal air are monitored continuously using a thermograph and a hygrograph.

5.6. In the absence of a system for automated collection of experimental data, temperatures and heat flow densities are measured around the clock every 3 hours (0; 3; 6; 9; 12; 15; 18; 21 hours). Air humidity in a room or climate chamber compartment is measured every 6 hours (0; 6; 12; 18 hours).

The measurement results are recorded in the observation log according to the form given in Appendix 4.

5.7. To establish the compliance of experimental values of heat transfer resistance with standardized requirements, the state of the enclosing structure (thickness and moisture content of layer materials, air permeability of joints) and test conditions (difference in pressure of internal and external air, wind speed) are determined.

The moisture content of the materials of the tested enclosing structures is determined upon completion of thermal testing. Samples are taken with a bolt from walls at a height of 1.0-1.5 m from the floor level, from coatings - in thermally homogeneous zones. Soft insulation is cut out with a knife or removed with a metal hook. Samples are collected in bottles and weighed on an analytical balance on the day they are taken. Drying samples to constant weight, weighing them and calculating the moisture content of materials is carried out in accordance with GOST 24816.

It is possible to determine the moisture content of materials without destroying the enclosing structures using the dielcometric method, by inserting capacitive transducers into the thickness of the fence during its manufacture, or by using moisture meters according to TU 25-05.2792.

For concrete enclosing structures, these measurements are carried out in accordance with GOST 21718.

The air permeability of the enclosing structure in laboratory and field conditions is determined before or at the end of thermal testing in accordance with GOST 25891.

The difference in pressure between internal and external air is measured during tests in laboratory conditions once a day, and in natural conditions after 3 hours, and the results are recorded in a separate journal.

Wind speed and direction are measured on the territory of the test building 4 times a day (0, 6, 12, 18 hours) at a distance of 1.5 to 2 building heights and at a distance of one height for buildings of 9 or more floors.

It is allowed to take the wind speed and direction according to the data of the nearest weather station.

6. Processing of results

6.1. Heat transfer resistance for a thermally homogeneous zone of the enclosing structure is calculated using the formula

	heat transfer resistance of the internal and external surfaces of the enclosing structure, respectively, mW;
	thermal resistance of a homogeneous zone of the enclosing structure, mW;
	average values of temperatures of internal and external air, respectively, over the calculated measurement period, °C;
	average temperature values for the internal and external surfaces of the enclosing structure, respectively, over the calculation period of measurements, °C;
	the average actual heat flux density over the calculated measurement period, W/m 2, determined by formulas (5) or (6).

6.2. The reduced resistance to heat transfer of a building envelope with uneven surface temperatures is calculated using the formula

	area of the tested enclosing structure, m;
	area of the characteristic isothermal zone determined by planimetry, m;
	heat transfer resistance of the characteristic zone mW, determined by formula (3) or (4).

6.3. The heat transfer resistance of a characteristic zone is determined by the formula

	heat transfer resistance of the internal and external surfaces of the characteristic zone, respectively, mW;
	thermal resistance of the characteristic zone, mW;
	average temperatures for the calculation period, respectively, of internal and external air at a distance of 100 mm from the surfaces of the characteristic zone, °C;
	average temperatures for the calculation period of the internal and external surfaces of the characteristic zone, respectively, °C;
	the average actual heat flux density over the calculation period passing through the characteristic zone, W/m, determined by formulas (5) or (6).

Heat transfer resistance of characteristic zones is allowed, calculated using the formula

6.4. When processing test results in laboratory conditions in climatic chambers with automatic control of temperature and humidity conditions, to calculate the heat transfer resistance for each section, the average temperatures and heat flux densities are taken over the entire test period.

When processing the results of full-scale tests, graphs of changes in time of characteristic temperatures and heat flow densities are constructed, from which periods with the most steady-state conditions are selected with a deviation of the average daily outdoor air temperature from the average value for this period within 1.5 and the average values of heat transfer resistance are calculated for each period.

The total duration of these calculation periods should be at least 1 day for enclosing structures with thermal inertia up to 1.5 and at least 3 days for structures with greater thermal inertia.

6.5. If the temperatures of the free ends of the thermocouples differ from 0, it is necessary to introduce a correction to the readings of the measured emf. in accordance with GOST 3044.

6.6. The average actual heat flux density over the measurement period is determined by the formulas:

for continuous enclosing structures

for enclosing structures with a closed air gap adjacent to the internal thin layer on which the heat flow converter is installed.

	the same as in formula (1);
	average measured heat flux density for the calculation period, W/m;
	thermal resistance of the heat flow converter, determined from its passport data, mW;
	thermal resistance of the layer attaching the heat flow converter, mW; determined by calculation;
	heat transfer resistance of the inner surface of the enclosing structure, mW, determined by calculation using the average values of and. It is allowed, as a first approximation, to take it equal to the standardized values of 0.115 mW;
	thermal resistance of the layer of the enclosing structure between the inner surface and the air gap, mW, determined by calculation;
	surface temperature of the heat flow converter facing the inside of the room, measured during testing;
	thermal resistance of a closed air gap, mW, determined according to Appendix 5.

For a ventilated layer, it is determined by the formula

where a=5.5+5.7u

6.7. Thermal resistance individual layers of the enclosing structure are determined by the formula

In order to compare the actual thermal conductivity values of the materials used in the structure with the design values, the thermal conductivity of the layer material is determined by the formula

where is the layer thickness, m.

6.8. The confidence interval for determining heat transfer resistance values is calculated using the formula

6.9. The relative error in determining the heat transfer resistance of the building envelope using this method should not exceed 15%.

6.10. The heat transfer resistance values obtained as a result of testing must be no less than the values specified in the standards, technical specifications for enclosing structures or design values.

The coefficient of thermal uniformity of the enclosing structure, taking into account the influence of joints, framing ribs and other heat-conducting inclusions, must be no lower than the values given in Appendix 6.

6.11. To establish compliance of the experimental values of the temperatures of the internal surface with the standardized values, the temperatures of the internal surface of the fence obtained as a result of testing are recalculated according to Appendix 7 to the design temperatures of the external and internal air and , accepted for specific type buildings and climatic region in accordance with GOST 12.1.005 and the project.

7. Safety requirements

7.1. When working with climate chamber equipment and when conducting tests in winter operating conditions of buildings, safety requirements must be observed in accordance with the Rules technical operation electrical installations of consumers and Rules technical safety during the operation of consumer electrical installations approved by Gosenergonadzor and General requirements electrical safety in construction according to GOST 12.1.013.

7.2. Installation of sensors on the outer surface of the enclosing structure on floors above the first should be carried out from loggias, balconies or installation aids in compliance with safety requirements when working at height.

List of instruments and equipment for determining resistance

heat transfer of enclosing structures

Thermocouples chromel-alumel or chromel-copel with an electrode diameter of 0.3 mm and a length of up to 25000 mm and PVC insulation in accordance with GOST 3044 and GOST 1790.

Heat flow meters ITP-11 or ITP-7 according to TU A10T2.825.013 TU.

Temperature probe-thermometer ETP-M according to TU-7-23-78.

Heat flow converters (heat meters) in accordance with GOST 7076.

Thermal imaging or thermoradiation system.

Aspiration psychrometer.

Meteorological weekly thermograph M-16I according to GOST 6416.

Meteorological weekly hygrograph M21N or M32N.

Laboratory thermometer type 4-1 (from minus 30 to plus 20C) according to GOST 27544.

Meteorological low-degree thermometer TM-9 according to GOST 112.

Meteorological thermometer TM-8 according to GOST 112.

Manual cup anemometer ME-13 or ARI-49 according to GOST 6376 or GOST 7193.

Dewar flask.

Micromanometer MMN according to GOST 11161.

Laboratory scales according to GOST 24104.

Cups type SV or SN according to GOST 25336.

A bolt with a diameter of 15 mm with a pobedit tip.

Electric drying cabinet according to OST 16.0.801.397.

Sledgehammer weighing up to 4 kg.

Stopwatch S-1-2-A.

Steel tape measure 10000 mm RZ-10.

Desiccator according to GOST 25336.

Instruments for automatic recording of thermocouple readings

Electronic potentiometer EPP-09MZ for 24 points or KSP-4 for 12 points, calibration for thermocouples ХК or in mV.

Electronic balancing strip chart recorder with 12 points, graduation in mV, measurement limit from minus 5 to plus 5 mV.

Electronic potentiometer with 12 points, graduation in mV, measurement limits from 0 to plus 10 mV.

Devices for manual recording of temperature sensor readings

Portable potentiometer PP-63, KP-59, R-306, R-305 or digital microvoltmeter V-7-21.

Panel switches 20 - point type PNT.

Note. It is allowed to use other instruments, equipment and measuring instruments that meet the requirements and are verified in the prescribed manner. Their quantity is determined in accordance with the test program and scheme.

Appendix 2

Information

Layout of thermocouples on the tested enclosure

designs and connecting them to measuring equipment

Floor planCentral

vertical (central)

Wall scan

1 - outer corner; 2 - joint of external panels; 3 - junction of outer and inner panels

Wall section and sensor connections

1 - working junctions of thermocouples; 2 - cold junction of thermocouples; 3 - heat flow converter; 4 - multi-point switch; 5 - measuring device; 6 - thermostat (Dewar vessel)

Example of determining the outdoor temperature range

and errors in calculating heat transfer resistance

building envelope

1. Determine the resistance to heat transfer of the external walls of a residential building in winter operating conditions of the building.

According to the design, heat transfer resistance outer wall over the main field is equal to mS/W. The average experimental value of heat transfer resistance is calculated from the measurement results using the formula

Heat flux density is measured with an ITP-11 device in accordance with GOST 25380 with a measurement limit of 50 W/m. Air temperature is measured mercury thermometers with a division price of 0.2°C.

2. In accordance with the theory of errors, in this case, the absolute total measurement error is determined by the formula

The main relative error of the ITP-11 device in percent is calculated using the formula

The main absolute measurement error with the ITP-11 device is calculated using the formula

The main absolute measurement error with mercury thermometers is taken equal to half the scale division value

Since the ratio to is negligible, it is not taken into account further.

The experimental value of the heat transfer resistance of the structure to be tested is taken approximately equal to its design value. Substituting formula (4) into formula (2), we get

Analysis of formula (5) shows that the larger the ratio, the greater the measurement error. When measuring heat flux density with an ITP-11 device, setting the measurement limit W/m and maintaining a relative measurement error of 5%, the current value of the measured heat flux density according to formula (3) will be equal to

W/m.

The absolute measurement error according to formula (5) for the main field of the wall with 1 mC/W will be:

maximum

mS/W;

minimum

mS/W.

When using the ITP-11 device during testing, it is necessary to ensure conditions under which the measured heat flux density would be in the range of 33-50 W/m.

The range of temperature differences providing this range of heat flux densities is determined.

From formula (1) of this appendix we obtain

Considering that , we get the following values:

;

The range of external temperatures at which it is necessary to test the external wall of a residential building, subject to the minimum range of total absolute measurement error, will be:

The timing of tests of enclosing structures in winter operating conditions of buildings is determined in accordance with the weather forecast for the period when external temperatures range from minus 15 to minus 32C. Under these conditions it will be used top part the first range scales of the ITP-11 device (from 33 to 50 W/m) and heat flux density measurements will be performed with minimal error.

If, as a result of the tests carried out, it was obtained that 1.04 mC/W, then the confidence interval, taking into account the total absolute measurement error calculated above, is presented in the form

GOST 26254-84

Group Zh39

STATE STANDARD OF THE USSR UNION

BUILDINGS AND CONSTRUCTIONS

Methods for determining heat transfer resistance

enclosing structures

Buildings and structures.

Methods for determination of thermal resistance

of enclosing structures

Date of introduction 1985-01-01

Information data

1. DEVELOPED

Scientific Research Institute of Building Structures (NIISK) of the USSR State Construction Committee

Central Research and Design Institute of Standard and Experimental Housing Design (TsNIIEPzhilishcha) of the State Civil Engineering

DEVELOPERS

INTRODUCED

Research Institute of Building Physics (NIISF) of the USSR State Construction Committee

Director V.A. Drozdov

2. APPROVED AND ENTERED INTO EFFECT by Resolution of the USSR State Committee for Construction Affairs dated August 2, 1984 No. 127

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE REGULATIVE AND TECHNICAL DOCUMENTS

GOST 12.1.005-88

GOST 12.1.013-78

GOST 112-78

GOST 1790-77

GOST 3044-84

GOST 6376-74

GOST 6416-75

GOST 6651-84

GOST 7076-87

GOST 7164-78

GOST 7165-78

GOST 7193-74

GOST 8711-78

GOST 9245-79

GOST 9736-91

GOST 9987-77

GOST 11161-84

GOST 16617-87

GOST 17083-87

GOST 21718-84

GOST 22787-77

GOST 23215-78

GOST 24104-88

GOST 24816-81

GOST 25336-82

GOST 25380-82

GOST 25891-83

GOST 27544-87

6.11, Appendix 7

7.1

3.4, Appendix 1

3.4, appendix 1

3.4, 6.5, Appendix 1

3.9, Appendix 1

3.5, Appendix 1

3.4

Annex 1

3.1

3.4

3.9, Appendix 1

3.4

3.1

3.6, Appendix 1

3.1

5.7

3.1

3.8, Appendix 1

5.7

3.8, Appendix 1

3.3, 4.12, 5.4, Appendix 3

5.7

3.4, Appendix 1

OST 16.0.801.397-87

OST 26-03-2039-87

TU 25-05.2792-82

3.8, Appendix 1

3.1

5.7

5.REISSUE. April 1994

This standard applies to enclosing structures of residential, public, industrial and agricultural buildings and structures: external walls, coverings, attic floors, floors over passages, cold undergrounds and basements, gates and doors in external walls, other enclosing structures separating rooms with different temperatures -humidity conditions, and establishes methods for determining their resistance to heat transfer in laboratory and full-scale (operational) winter conditions.

The standard does not apply to translucent enclosing structures.

Determining the heat transfer resistance of enclosing structures allows one to quantify the thermal technical qualities of the enclosing structures of buildings and structures and their compliance with regulatory requirements, establish real heat losses through external enclosing structures, and check design and design solutions.

1. General Provisions

1.3. Methods for determining heat transfer resistance, based on creating conditions of stationary heat exchange in the enclosing structure and measuring the temperature of the internal and external air, the temperature of the surfaces of the enclosing structure, as well as the density of the heat flow passing through it, from which the corresponding required values are calculated using formulas (1) and ( 2) this standard.

2. Sampling method

2.1. Heat transfer resistance in laboratory conditions is determined on samples, which are entire elements of factory-made enclosing structures or their fragments.

2.2. The length and width of the tested fragment of the enclosing structure must be at least four times greater than its thickness and be at least 1500x1000 mm.

2.3. The procedure for selecting samples for testing and their number are established in the standards or technical specifications for specific enclosing structures. If these documents do not indicate the number of samples to be tested, at least two samples of the same type are selected for testing.

2.6. During full-scale testing of external walls, walls are selected in the corner room on the ground floor, oriented to the north, north-east, north-west and, additionally, in accordance with the tasks being solved, to other sides of the horizon, the most unfavorable for the given area (predominant winds, oblique rains, etc.) .d.), and on another floor.

2.7. For testing, at least two similar enclosing structures are selected, on the inside of which the same temperature and humidity conditions are maintained in the premises.

3. Apparatus and equipment

To complete the climatic chamber, the following equipment is used:

compressors with a refrigeration capacity of at least 3.5 kW or compressor-condenser units of refrigeration machines in accordance with OST 26-03-2039, installed outside the chamber, and cooling batteries of refrigeration units installed inside the cold compartment to cool the air in it;

3.3. To measure the density of heat flows passing through the building envelope, instruments in accordance with GOST 25380 are used.

DC potentiometers in accordance with GOST 9245, millivoltmeters in accordance with GOST 8711 or GOST 9736 are used as secondary measuring instruments working with thermoelectric thermometers and heat flow converters. Resistance thermometers are connected to DC measuring bridges in accordance with GOST 7165.

To quickly measure the temperature field of the surfaces of the enclosing structure, temperature probes, thermoradiometers, and thermal imagers are used (see Appendix 1).

The air temperature is controlled using glass expansion thermometers in accordance with GOST 112 (lower limit minus 70 C) and GOST 27544.

It is allowed to use other primary temperature transducers and devices, verified in accordance with the established procedure.

3.5. To continuously record the nature of changes in indoor air temperature, thermographs are used in accordance with GOST 6416.

3.6. To measure the difference in air pressure on both sides of the structure being tested, a micromanometer MMN according to GOST 11161 is used.

3.9. Wind speed in natural conditions is determined with a hand-held anemometer according to GOST 6376 or GOST 7193.

3.10. To check the operation of the climatic chamber equipment, measuring equipment and heat exchange conditions in the warm and cold compartments of the chamber, use a control fragment with a known thermal resistance in the range of 1-2 (m)/W, the overall dimensions of which must correspond to the dimensions and configuration of the opening into which the test is installed design. The design solution and material of the control fragment must ensure that its thermal properties remain constant over time. The climate chamber is checked at least once a year.

3.11. The list of instruments and equipment for determining the heat transfer resistance of enclosing structures in laboratory and field conditions is given in Appendix 1.

4. Preparation for testing

4.2. The layout of the primary temperature and heat flow transducers is drawn up on the basis of the design solution of the structure or according to a pre-established temperature field of the surface of the enclosing structure being tested. To do this, when testing in climatic chambers or pavilions, the fully assembled enclosing structure is subjected to temporary thermal exposure using the equipment specified in clause 3.1, after which, without waiting for the establishment of a stationary mode, in order to identify heat-conducting inclusions and thermally homogeneous zones, their configuration and sizes , remove the temperature field using a thermal imager, thermoradiometer and temperature probe. The contours of the main temperature zones, based on the results of thermography, are applied to the surface of the enclosing structure.

During full-scale tests, they immediately begin to measure surface temperatures and establish thermally homogeneous zones and locations of heat-conducting inclusions.

4.4. When measuring temperatures with a temperature probe, the internal and external surfaces of the enclosing structure are divided into squares with sides no more than 500 mm. Zones with heat-conducting inclusions are divided into smaller squares in accordance with design features. The surface temperature is measured at the vertices of these squares and directly against the heat-conducting inclusions. Temperature values are applied to the sketch of the enclosing structure. Points with equal temperatures are connected by isotherms, and the configuration and dimensions of isothermal zones are determined. To identify thermally homogeneous areas, it is permissible to limit oneself to measuring the temperatures of the internal surface of the enclosing structure if it is impossible to measure temperatures from the outside.

If necessary, the layout of the primary sensors is specified based on the results of thermography of the surface of the tested enclosing structure.

Heat flow converters are fixed on the inner and outer surfaces of the fence being tested, at least two on each surface.

4.11. The sensitive elements of the temperature sensors are tightly attached to the surface of the structure being tested.

In this case, the thermometric wire is removed from the place where the sensitive element is attached along the surface of the enclosing structure in the direction of isotherms or the minimum temperature gradient to a length of at least 50 wire diameters. The electrical insulation resistance between the thermal converter circuit and external metal fittings must be at least 20 MOhm at a temperature (and relative humidity of 30 to 80%).

The thermocouples are connected to the secondary measuring instrument through an intermediate multipoint switch.

4.13. To measure the difference in air pressure, the ends of the hoses from the micromanometer are placed on both sides of the structure under test at a level of 1000 mm from the floor.

4.15. When testing in a climate chamber, after checking the readiness of the equipment and measuring instruments, the warm and cold compartments are isolated from the outside air using sealed doors. The control equipment sets the specified temperature and air humidity in each compartment and turns on the refrigeration, heating and air-humidifying equipment of the chamber.

5. Testing

5.1. When testing in laboratory conditions, the temperature and relative humidity of the air in the climate chamber compartments are maintained automatically with accuracy and %.

After establishing a given air temperature in the climatic chamber compartments, measurements are made for enclosing structures with thermal inertia up to 1.5 after at least 1.5 days, with thermal inertia from 1.5 to 4 - after 4 days, and thermal inertia from 4 to 7 - after 7 days, and with thermal inertia over 7 - after 7.5 days.

The thermal inertia values of enclosing structures are determined according to the building codes and regulations approved by the USSR State Construction Committee.

The number of measurements in a stationary mode must be at least 10 with a total measurement duration of at least 1 day.

The duration of measurements under natural conditions is determined by the results of preliminary processing of measurement data during testing, which takes into account the stability of the outside air temperature during the test period and in the previous days and the thermal inertia of the enclosing structure. The duration of measurements under natural operating conditions should be at least 15 days.

5.4. The heat flux density passing through the enclosing structure is measured according to GOST 25380.

5.5. The temperature and humidity of the internal air are monitored continuously using a thermograph and a hygrograph.

The measurement results are recorded in the observation log according to the form given in Appendix 4.

For concrete enclosing structures, these measurements are carried out in accordance with GOST 21718.

The air permeability of the enclosing structure in laboratory and field conditions is determined before or at the end of thermal testing in accordance with GOST 25891.

It is allowed to take the wind speed and direction according to the data of the nearest weather station.

6. Processing of results

6.1. Heat transfer resistance for a thermally homogeneous zone of the enclosing structure is calculated using the formula


where and	heat transfer resistance of the internal and external surfaces of the enclosing structure, respectively, m W;
	thermal resistance of a homogeneous zone of the enclosing structure, m W;
	average temperature values of internal and external air, respectively, for the calculated period of measurements, ;
	average temperature values for the internal and external surfaces of the enclosing structure, respectively, over the calculated measurement period;
	the average actual heat flux density over the calculated measurement period, W/m, determined by formulas (5) or (6).

6.2. The reduced resistance to heat transfer of a building envelope with uneven surface temperatures is calculated using the formula


Where	area of the tested enclosing structure, m;
	area of the characteristic isothermal zone determined by planimetry, m;
	heat transfer resistance of the characteristic zone m W, determined by formula (3) or (4).

6.3. The heat transfer resistance of a characteristic zone is determined by the formula


where and	heat transfer resistance of the internal and external surfaces of the characteristic zone, respectively, m W;
	thermal resistance of the characteristic zone, m W;
	average temperatures for the calculation period of the internal and external air, respectively, at a distance of 100 mm from the surfaces of the characteristic zone, ;
	average temperatures for the calculation period of the internal and external surfaces of the characteristic zone, respectively, ;
	average actual heat flux density over the calculation period passing through the characteristic zone, W/m Determined by formulas (5) or (6).

Heat transfer resistance of characteristic zones is allowed, calculated using the formula

Where

The total duration of these calculation periods should be at least 1 day for enclosing structures with thermal inertia up to 1.5 and at least 3 days for structures with greater thermal inertia.

6.5. If the temperatures of the free ends of the thermocouples differ from 0, it is necessary to introduce a correction to the readings of the measured emf. in accordance with GOST 3044.

6.6. The average actual heat flux density over the measurement period is determined by the formulas:

for continuous enclosing structures

for enclosing structures with a closed air gap adjacent to the internal thin layer on which the heat flow converter is installed. And

total absolute error of the test result, calculated according to Appendix 3, m W.

6.9. The relative error in determining the heat transfer resistance of the building envelope using this method should not exceed 15%.

6.11. To establish compliance of the experimental values of the internal surface temperatures with the standardized values, the temperatures of the internal surface of the fence obtained as a result of tests are recalculated according to Appendix 7 to the calculated temperatures of external and internal air and , accepted for a specific type of building and climatic region in accordance with GOST 12.1.005 and the project.

BUILDINGS AND CONSTRUCTIONS

METHODS FOR DETERMINING RESISTANCE
HEAT TRANSFER OF ENCLOSING STRUCTURES

GOST 26254-84

PUBLISHING HOUSE OF STANDARDS
Moscow

STATE STANDARD OF THE USSR UNION

Date of introduction 01.01.85

This standard applies to enclosing structures of residential, public, industrial and agricultural buildings and structures: external walls, coverings, attic floors, floors over passages, cold undergrounds and basements, gates and doors in external walls, other enclosing structures separating rooms with different temperatures -humidity conditions, and establishes methods for determining their resistance to heat transfer in laboratory and full-scale (operational) winter conditions.

The standard does not apply to translucent enclosing structures.

Determining the heat transfer resistance of enclosing structures makes it possible to quantify the thermal technical qualities of the enclosing structures of buildings and structures and their compliance with regulatory requirements, establish real heat losses through external enclosing structures, and check design and design solutions.

1. General Provisions

1.1. Heat transfer resistance R 0, which characterizes the ability of the enclosing structure to resist the heat flow passing through it, is determined for sections of the enclosing structure that have a uniform surface temperature.

1.3. Methods for determining heat transfer resistance, based on creating conditions of stationary heat exchange in the enclosing structure and measuring the temperature of internal and external air, the temperature of the surfaces of the enclosing structure, as well as the density of the heat flow passing through it, from which the corresponding required values are calculated using formulas () and () of this standard.

2. Sampling method

2.1. Heat transfer resistance in laboratory conditions is determined on samples, which are entire elements of factory-made enclosing structures or their fragments.

2.2. The length and width of the tested fragment of the enclosing structure must be at least four times its thickness and be at least 1500 ´ 1000 mm.

2.7. For testing, at least two similar enclosing structures are selected, on the inside of which the same temperature and humidity conditions are maintained in the premises.

3. Apparatus and equipment

To complete the climatic chamber, the following equipment is used:

To quickly measure the temperature field of the surfaces of the enclosing structure, temperature probes, thermoradiometers, and thermal imagers are used (see Appendix).

The air temperature is controlled using glass expansion thermometers according to GOST 112 (lower limit minus 70 ° C) and GOST 27544.

It is allowed to use other primary temperature transducers and devices, verified in accordance with the established procedure.

3.10. To check the operation of the climate chamber equipment, measuring equipment and heat exchange conditions in the warm and cold compartments of the chamber, a control fragment with a known thermal resistance in the range of 1 - 2 (m 2 × ° C) / W is used, the overall dimensions of which must correspond to the dimensions and configuration of the opening, into which the structure under test is installed. The design solution and material of the control fragment must ensure that its thermal properties remain constant over time. The climate chamber is checked at least once a year.

3.11. The list of instruments and equipment for determining the heat transfer resistance of enclosing structures in laboratory and field conditions is given in the Appendix.

4. Preparation for testing

4.2. The layout of the primary temperature and heat flow transducers is drawn up on the basis of the design solution of the structure or according to a pre-established temperature field of the surface of the enclosing structure being tested. To do this, when testing in climatic chambers or pavilions, a fully assembled enclosing structure is subjected to temporary thermal exposure using the equipment specified in paragraph , after which, without waiting for the establishment of a stationary mode, in order to identify heat-conducting inclusions and thermally homogeneous zones, their configuration and sizes, measure the temperature field using a thermal imager, thermoradiometer and temperature probe. The contours of the main temperature zones, based on the results of thermography, are applied to the surface of the enclosing structure.

During full-scale tests, they immediately begin to measure surface temperatures and establish thermally homogeneous zones and locations of heat-conducting inclusions.

4.4. When measuring temperatures with a temperature probe, the internal and external surfaces of the enclosing structure are divided into squares with sides no more than 500 mm. Zones with heat-conducting inclusions are divided into smaller squares in accordance with design features. The surface temperature is measured at the vertices of these squares and directly against the heat-conducting inclusions. Temperature values are applied to the sketch of the enclosing structure. Points with equal temperatures are connected by isotherms, and the configuration and dimensions of isothermal zones are determined. To identify thermally homogeneous areas, it is permissible to limit oneself to measuring the temperatures of the internal surface of the enclosing structure if it is impossible to measure temperatures from the outside.

If necessary, the layout of the primary sensors is specified based on the results of thermography of the surface of the tested enclosing structure.

4.13. To measure the difference in air pressure, the ends of the hoses from the micromanometer are placed on both sides of the structure under test at a level of 1000 mm from the floor.

4.15. When testing in a climate chamber, after checking the readiness of the equipment and measuring instruments, the warm and cold compartments are isolated from the outside air using sealed doors. The control equipment sets the specified temperature and air humidity in each compartment and turns on the refrigeration, heating and air-humidifying equipment of the chamber.

5. Testing

5.1. When testing in laboratory conditions, the temperature and relative humidity in the climate chamber compartments are maintained automatically with an accuracy of ± 1 ° C and ± 5%.

The thermal inertia values of enclosing structures are determined according to the building codes and regulations approved by the USSR State Construction Committee.

The number of measurements in a stationary mode must be at least 10 with a total measurement duration of at least 1 day.

5.5. The temperature and humidity of the internal air are monitored continuously using a thermograph and a hygrograph.

The measurement results are recorded in the observation log according to the form given in the Appendix.

The moisture content of the materials of the tested enclosing structures is determined upon completion of thermal testing. Samples are taken with a bolt from walls at a height of 1.0 - 1.5 m from the floor level, from coatings - in thermally homogeneous zones. Soft insulation is cut out with a knife or removed with a metal hook. Samples are collected in bottles and weighed on an analytical balance on the day they are taken. Drying samples to constant weight, weighing them and calculating the moisture content of materials is carried out in accordance with GOST 24816.

For concrete enclosing structures, these measurements are carried out in accordance with GOST 21718.

The air permeability of the enclosing structure in laboratory and field conditions is determined before or at the end of thermal testing in accordance with GOST 25891.

It is allowed to take the wind speed and direction according to the data of the nearest weather station.

6. Processing of results

6.1. Heat transfer resistance R 0 for a thermally homogeneous zone of the enclosing structure is calculated using the formula

Where R in and R n - heat transfer resistance of the internal and external surfaces of the enclosing structure, respectively, m 2 ×° C/W;

R k - thermal resistance of a homogeneous zone of the enclosing structure, m 2 ×° C/W;

t in and t n - average temperature values of internal and external air, respectively, for the calculated measurement period, ° C;

t in and t n - average temperature values for the calculated period of measurements, respectively, of the internal and external surfaces of the enclosing structure, ° C;

q f - average actual heat flux density over the calculated measurement period, W/m 2, determined by formulas () or ().

6.2. The reduced resistance to heat transfer of a building envelope with uneven surface temperatures is calculated using the formula

Where F- area of the tested enclosing structure, m2;

F i- area of the characteristic isothermal zone determined by planimetry, m 2 ;

R oi- heat transfer resistance of the characteristic zone m 2 × ° C/W, determined by the formula () or ().

6.3. The heat transfer resistance of a characteristic zone is determined by the formula

Where R to i And R n i- heat transfer resistance of the internal and external surfaces of the characteristic zone, respectively, m 2 × ° C/W;

R to i- thermal resistance of the characteristic zone, m 2 × ° C/W;

t to i And t n i- average temperatures of internal and external air for the calculation period, respectively, at a distance of 100 mm from the surfaces of the characteristic zone, ° C;

t to i And t n i- average temperatures for the calculation period, respectively, of the internal and external surfaces of the characteristic zone, ° C;

q f i- average actual heat flux density passing through the characteristic zone for the calculation period, W/m2, determined by formulas () or ().

Heat transfer resistance of characteristic zones is allowed R oi, calculate using the formula

;

a to i And a l i- coefficients of convective and radiant heat transfer, respectively, of the inner surface of the characteristic zone, W/(m 2 × ° C), determined by the drawing. and applications.

When processing the results of full-scale tests, graphs of changes in time of characteristic temperatures and heat flow densities are constructed, from which periods with the most steady-state conditions are selected with a deviation of the average daily outside air temperature from the average value for this period within ± 1.5 ° C and the average resistance values are calculated heat transfer for each period.

The total duration of these calculation periods should be at least 1 day for enclosing structures with thermal inertia up to 1.5 and at least 3 days for structures with greater thermal inertia.

for enclosing structures with a closed air gap adjacent to the internal thin layer on which the heat flow converter is installed.

Where t in, t n, t in, t n- the same as in formula ();

q- average measured heat flux density for the calculation period, W/m2;

R T- thermal resistance of the heat flow converter, determined from its passport data, m 2 × ° C/W;

R C- thermal resistance of the layer attaching the heat flow converter, m 2 × ° C/W; determined by calculation;

R in- heat transfer resistance of the inner surface of the enclosing structure, m 2 × ° C/W, determined by calculation using average values t in, t in, And q. It is allowed, as a first approximation, to take it equal to the standardized values of 0.115 m 2 ×° C/W;

R 1- thermal resistance of the layer of the enclosing structure between the inner surface and the air gap, m 2 × ° C/W, determined by calculation;

t T.v- surface temperature of the heat flow converter facing the inside of the room, ° C, measured during testing;

R v.p- thermal resistance of a closed air layer, m 2 × ° C/W, determined by application.

For a ventilated layer R v.p determined by the formula

where a = 5.5 + 5.7 v;

v- speed of air movement in the layer, determined from experimental data or calculation, m/s;

a l- radiant heat transfer coefficient, determined by calculation, W/(m 2 × ° C).

6.7. The thermal resistance of individual layers of the enclosing structure is determined by the formula

where Dt is the temperature difference at the layer boundaries, ° C;

In order to compare the actual thermal conductivity values of the materials used in the structure with the design values, the thermal conductivity of the layer material l determined by the formula

Where d- layer thickness, m.

6.8. Confidence interval for determining heat transfer resistance values R o.i calculated by the formula

; (10)

where is the average heat transfer resistance determined during testing of the enclosing structure using the formula (), (), m 2 × ° C/W;

The total absolute error of the test result, calculated according to the application, m 2 ×° C/W.

6.9. The relative error in determining the heat transfer resistance of the enclosing structure using this method should not exceed 15%.

6.10. Heat transfer resistance values obtained as a result of tests R o and must be no less than the values specified in the standards, technical specifications for enclosing structures or design values.

7.2. Installation of sensors on the outer surface of the enclosing structure on floors above the first must be carried out from loggias, balconies or mounting facilities in compliance with safety requirements when working at height.

Annex 1
Recommended

Thermocouples chromel-alumel or chromel-copel with an electrode diameter of 0.3 mm and a length of up to 25000 mm and PVC insulation in accordance with GOST 3044 and GOST 1790.

Heat flow meters ITP-11 or ITP-7 according to TU A10T2.825.013 TU.

Temperature probe-thermometer ETP-M according to TU-7-23-78.

Heat flow converters (heat meters) in accordance with GOST 7076.

Thermal imaging or thermoradiation system.

Aspiration psychrometer.

Meteorological weekly thermograph M-16I according to GOST 6416.

Meteorological weekly hygrograph M21N or M32N.

Laboratory thermometer type 4-1 (from minus 30 to plus 20 ° C) according to GOST 27544.

Meteorological low-degree thermometer TM-9 according to GOST 112.

Meteorological thermometer TM-8 according to GOST 112.

Manual cup anemometer ME-13 or ARI-49 according to GOST 6376 or GOST 7193.

Dewar flask.

Micromanometer MMN according to GOST 11161.

Cups type SV or SN according to GOST 25336.

A bolt with a diameter of 15 mm with a pobedit tip.

Electric drying cabinet according to OST 16.0.801.397.

Sledgehammer weighing up to 4 kg.

Stopwatch S-1-2-A.

Steel tape measure 10000 mm RZ-10.

Instruments for automatic recording of thermocouple readings

Electronic potentiometer EPP-09MZ for 24 points or KSP-4 for 12 points, calibration for thermocouples ХК or in mV.

Electronic balancing strip chart recorder with 12 points, graduation in mV, measurement limit from minus 5 to plus 5 mV.

Electronic potentiometer with 12 points, graduation in mV, measurement limits from 0 to plus 10 mV.

Devices for manual recording of temperature sensor readings

Portable potentiometer PP-63, KP-59, R-306, R-305 or digital microvoltmeter V-7-21.

Panel switches 20 - point type PNT.

Note . It is allowed to use other instruments, equipment and measuring instruments that meet the requirements and are verified in the prescribed manner. Their quantity is determined in accordance with the test program and scheme.

Appendix 2
Information

Floor plan Central vertical (c.v.)

Wall scan

1 - outer corner; 2 - joint of external panels; 3 - junction of external and internal panels

Wall section and sensor connections

1 - working junctions of thermocouples; 2 - cold junction of thermocouples; 3 - heat flow converter;
4 - multi-point switch; 5 - measuring device; 6 - thermostat (Dewar vessel)

Appendix 3
Recommended

1. Determine the resistance to heat transfer of the external walls of a residential building in winter operating conditions of the building.

According to the project, the heat transfer resistance of the outer wall along the main field is equal to R o.p.= 1 m 2 ×° C/W. Average experimental value of heat transfer resistance R o.e. calculated from measurement results using the formula

where is the average temperature of the internal and external air, respectively, during the test periods, ° C;

Average density heat flow passing through the fence, W/m2.

Heat flux density is measured with an ITP-11 device in accordance with GOST 25380 with a measurement limit set at 50 W/m2. Air temperature is measured with mercury thermometers with a division value of 0.2 ° C.

2. In accordance with the theory of errors, in this case the absolute total measurement error D R S determined by the formula

Where Dq- absolute measurement error of heat flux density, W/m2;

D (D t meas) - absolute error in measuring the temperature difference, ° C.

The main relative error of the ITP-11 device e q as a percentage calculated by the formula

Where q pr- value of the measurement limit, W/m 2 ;

q meas.- value of the measured heat flux density, W/m2.

The main absolute error of measurement by the ITP-11 device Dq calculated by the formula

The main absolute measurement error with mercury thermometers is taken equal to half the scale division value

D ( D t) = 0.5 × 0.2 = 0.1 ° C.

Since the ratio D ( D tmeas.) To D t is negligible, then it is not taken into account in the future.

The experimental value of heat transfer resistance of the structure to be tested is taken approximately equal to its design value R o.p.. Substituting formula () into formula (), we get

Characteristics of the building envelope

Numbers of thermally homogeneous zones of structures

Numbers of installed temperature sensors

Current surface temperatures

Average temperature of a thermally homogeneous zone

Heat flow sensor numbers

Current values of heat flux density

Average heat flux density

Numbers of sensors for measuring relative air humidity

Current values of relative air humidity, %

Average relative air humidity, %

Notes

t to i, ° C

t n i, ° C

t to i, ° C

t n i, ° C

W/m2

Air layer thickness, m	Thermal resistance of a closed air layerR v.p, m 2 × ° C/W
	horizontal with heat flow from bottom to top and vertical		horizontal with heat flow from top to bottom
	at air temperature in the layer
	positive	negative	positive	negative
0,01	0,13	0,15	0,14	0,15
0,02	0,14	0,15	0,15	0,19
0,03	0,14	0,16	0,16	0,21
0,05	0,14	0,17	0,17	0,22
	0,15	0,18	0,18	0,23
0,15	0,15	0,18	0,19	0,24
0,2 - 0,3	0,15	0,19	0,19	0,24

Note . When pasting one or both surfaces of the air gap aluminum foil The thermal resistance should be doubled.

Appendix 6
Information

Thermal homogeneity coefficient of the enclosing structure r,
taking into account the influence of joints, framing ribs and other heat conductors
inclusions, for the main most common external walls

Type of walls and materials used	Coefficient
Made from single-layer lightweight concrete panels	0,85 - 0,90
From three-layer reinforced concrete panels with effective insulation and flexible connections	0,75 - 0,85
Made from three-layer reinforced concrete panels with effective insulation and reinforced concrete dowels or expanded clay concrete ribs	0,70 - 0,80
Made from three-layer reinforced concrete panels with effective insulation and reinforced concrete ribs	0,50 - 0,65
Made from three-layer panels based on wood, asbestos cement and others sheet materials With effective insulation for sheet-by-sheet assembly with panel widths of 6 and 12 m without frame	0,90 - 0,95
From three-layer metal panels with foam insulation without frames in the joint area	0,85 - 0,95
Made of three-layer metal panels with foam insulation with a frame in the joint area	0,65 - 0,80
Made from three-layer metal panels with insulation from mineral wool with different frames	0,55 - 0,85
Made from three-layer asbestos-cement panels with mineral wool insulation with different frames	0,50 - 0,75

Note . Coefficient valuerdetermined based on calculations of temperature fields or experimentally.

Appendix 7
Recommended

RECALCULATION OF THE INNER SURFACE TEMPERATURE
OF THE FENCE OBTAINED AS A RESULT OF TESTS,
FOR DESIGN TEMPERATURE CONDITIONS